Taconite ore is a lean iron ore material extensively found in the Lake Superior region of the United States. The ore is generally composed of up to about 1 percent iron silicate, about 1 to 10 percent magnetite, about 1 to 30 percent hematite, and the remainder consisting primarily of quartz. Taconite rock is usually mined by open pit methods. It is then pulverized and the granulated material is subjected to magnetic extraction. The resultant tailings have been considered to be of little or no value, particularly since further extraction of the residual iron materials still contained therein is economically unfeasible. As a result, the taconite tailings have been discarded by depositing them into natural waterbodies, artificial ponds, etc. and have heretofore been a major source of pollution.
On the other hand, various organic resins have been used extensively in molding operations. These resins include those materials which are capable of undergoing further polymerization or polyaddition reactions during the molding process. The resins are normally mixed with fillers, dilutents, plasticizers, and/or other auxiliary agents. These agents include various organic compounds or polymers as well as various inorganic compounds, such as glass, carbon, metals, metal oxides or metal salts. The particular additives used are generally dependent upon the ability of the resin to incorporate the additive and the end product desired. Such compositions have been known in which the filler is the dominant component and these compositions have normally resulted in products which have a relatively low density or are easily friable. These compositions are so highly filled that it has been found that products formed from these materials would not be capable of withstanding large forces or stresses. In many instances they would not be of sufficient strength to support bending forces due to their own weight.
I have found that taconite iron ore material, particularly tailings which contain at least one percent (1%) magnetite therein, can be converted into a useful composition, the physical properties of which so nearly resemble natural slate that end use products previously made of natural slate can now be molded of my inventive composition.